Influence of dietary capsaicin and onion on the metabolic abnormalities associated with streptozotocin induced diabetes mellitus

Quantification of quercetin from red onion (Allium cepa L.) powder via high-performance liquid chromatography-ultraviolet (HPLC-UV) and its effect on hyperuricemia in male healthy Wistar albino rats

Onions (Allium cepa L.) contain various flavonols, including quercetin, kaempferol, anthocyanin, luteolin, and myricetin. Quercetin in onions is considered the primary bioactive component. To assess the impact of quercetin on hyperuricemia in healthy Wistar albino rats, this study used high-performance liquid chromatography with ultraviolet (HPLC-UV) to identify and measure quercetin in onion powder. Twenty-four 160 ± 10 g, six wistar albino male rats in each group were kept: NC (control sample, no onion powder), OT1, OT2, and OT3, which contained 11.13, 14.84, and 18.61 g/100 g onion powder, respectively. The treatment lasted 28 days, during which the last 7 days were for urine, feces, and blood collection. The results showed a trend of decreasing levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, total bilirubin, total cholesterol, and low-density lipoprotein in rats fed OT1, OT2, and OT3 diets. Improvements were observed in feed, water, and nutrient intake, feed conversion ratio, feed efficiency ratio, nutrient digestibility, nitrogen balance, body weight, blood urea nitrogen, creatinine, and uric acid levels (p ≤ .05). In contrast, high-density lipoprotein, triglycerides, serum total protein, neutrophils, and lymphocytes did not change (p ≥ .05). White blood cells, red blood cell count, platelet count, hemoglobin, and monocytes showed an upward trend. Based on our calculations, we determined the optimal human dosage from the most effective amount of onion powder. By taking into account the ratio of human-to-rat surface area, we estimate that the equivalent human dose of onion is 181.04 grams with 204 mg of quercetin. Additionally, when factoring in the dry matter content, the recommended dose of onion is 29.19 grams with 220 mg of quercetin.

Antiobesity effects of onion (Allium cepa) in subjects with obesity: Systematic review and meta-analysis

Onions are rich in bioactive compounds and have been found to prevent various chronic diseases, including obesity. We performed a systematic review and meta-analysis to investigate the antiobesity effect of onions. Studies were identified in PubMed/MEDLINE, Embase, Web of Science, and CENTRAL focusing on clinical trials evaluating the antiobesity effects of onion in obese subjects. The risk of bias in the studies was evaluated using Cochrane's Risk of Bias tool. The effect of onions was analyzed using data from the selected studies, and the results were indicated by weighted mean difference with 95% CI. The I 2 static test was used to examine heterogeneity between the studies. A total of 38 studies were reviewed, of which five clinical trials meeting the criteria were selected. As investigational products, onion peels were used in four studies and onions were used in one study. Following systematic review, it was determined that the risk of bias was generally low, and body weight, BMI, waist circumference, and triglyceride levels were significantly reduced in the onion groups compared to the placebo. In conclusion, onion intake had an antiobesity effect by reducing body weight and body fat, and this effect was particularly pronounced with onion peel.

Effects of garlic, onion, and apple cider vinegar as a herbal mixture on performance and blood traits of broilers inoculated with chicken infectious anemia virus

This study assessed the effects of a herbal mixture (HM) to protect poultry against chicken infectious anemia (CIA) and to modulate the adverse effects of this virus on performance, mortality, blood profile, white blood cells (WBCs) count, liver enzymes, liver histopathology, and intestinal morphology. Therefore, 240 one-day-old male broiler chicks (Ross 308) were divided into four experimental groups, with six replicates and ten chicks per group. The experimental groups consisted of a control group and groups with 2.5%, 5%, and 7.5% HM, all based on corn-soybean meal. All chicks were inoculated with the CIA virus (CIAV) on day 7. The results showed that supplementation of 2.5% of HM to broiler diet increased feed intake (FI) (P < 0.05) and also increased body weight (BW) and weight gain (WG) slightly (P > 0.05). Adding 7.5% HM caused a reversible decrease in FI, BW, and WG and increased FCR. Compared with the control group, mortality rates declined with an additional dose of HM in CIAV-infected chickens. HM supplementation in the diet of CIAV-infected chickens increased hematocrit (HCT), hemoglobin (Hb), and mean corpuscular volume (MCV) and decreased mean corpuscular hemoglobin concentration (MCHC) compared to the control (P < 0.05). Lymphocyte percentage and lymphocyte/heterophile ratio increased in HM-supplemented groups, especially at 2.5% (P < 0.05), and heterophile and granulocyte percentages were reduced (P < 0.05). Liver enzyme alkaline phosphatase (ALP) and liver steatosis declined in the 2.5% HM-treated group compared to the control (P < 0.05). It was concluded that adding 2.5% of the HM to the CIAV-infected broiler's diet did not negatively affect chicken performance. In addition to its hypolipidemic effects, it could prevent HCT and Hb from decreasing in chicks infected with CIAV and positively affect leukocyte types and liver enzymes. Interestingly, an additional dose of HM in the diet of the CIAV-infected broilers reduced mortality. Therefore, adding 2.5% of HM could prevent the adverse effects of CIA on hematological traits in broiler chicken flocks without adverse effects on performance.

Pomegranate peel extract protects against the development of diabetic cardiomyopathy in rats by inhibiting pyroptosis and downregulating LncRNA-MALAT1

Background: Pyroptosis is an inflammatory programmed cell death accompanied by activation of inflammasomes and maturation of pro-inflammatory cytokines interleukin-1β (IL-1β) and IL-18. Pyroptosis is closely linked to the development of diabetic cardiomyopathy (DC). Pomegranate peel extract (PPE) exhibits a cardioprotective effect due to its antioxidant and anti-inflammatory properties. This study aimed to investigate the underlying mechanisms of the protective effect of PPE on the myocardium in a rat model of DC and determine the underlying molecular mechanism.

Methods: Type 1 diabetes (T1DM) was induced in rats by intraperitoneal injection of streptozotocin. The rats in the treated groups received (150 mg/kg) PPE orally and daily for 8 weeks. The effects on the survival rate, lipid profile, serum cardiac troponin-1, lipid peroxidation, and tissue fibrosis were assessed. Additionally, the expression of pyroptosis-related genes (NLRP3 and caspase-1) and lncRNA-MALAT1 in the heart tissue was determined. The PPE was analyzed using UPLC-MS/MS and NMR for characterizing the phytochemical content.

Results: Prophylactic treatment with PPE significantly ameliorated cardiac hypertrophy in the diabetic rats and increased the survival rate. Moreover, prophylactic treatment with PPE in the diabetic rats significantly improved the lipid profile, decreased serum cardiac troponin-1, and decreased lipid peroxidation in the myocardial tissue. Histopathological examination of the cardiac tissues showed a marked reduction in fibrosis (decrease in collagen volume and number of TGF-β-positive cells) and preservation of normal myocardial structures in the diabetic rats treated with PPE. There was a significant decrease in the expression of pyroptosis-related genes (NLRP3 and caspase-1) and lncRNA-MALAT1 in the heart tissue of the diabetic rats treated with PPE. In addition, the concentration of IL-1β and caspase-1 significantly decreased in the heart tissue of the same group. The protective effect of PPE on diabetic cardiomyopathy could be due to the inhibition of pyroptosis and downregulation of lncRNA-MALAT1. The phytochemical analysis of the PPE indicated that the major compounds were hexahydroxydiphenic acid glucoside, caffeoylquinic acid, gluconic acid, citric acid, gallic acid, and punicalagin.

Conclusion: PPE exhibited a cardioprotective potential in diabetic rats due to its unique antioxidant, anti-inflammatory, and antifibrotic properties and its ability to improve the lipid profile. The protective effect of PPE on DC could be due to the inhibition of the NLRP3/caspase-1/IL-1β signaling pathway and downregulation of lncRNA-MALAT1. PPE could be a promising therapy to protect against the development of DC, but further clinical studies are recommended.

The Association Between Fasting Blood Sugar and Index of Nutritional Quality in Adult Women

Aim

It's unclear whether diet quality affects glycemic management. The index of nutritional quality (INQ) can examine diets both quantitatively and qualitatively (INQ). Hence, this study aimed to determine whether INQ and fasting blood sugar (FBS) are related among Iranian women.

Methods

This cross-sectional study was conducted on 360 adult Iranian women. Data were collected on the participants' general characteristics, medical history, anthropometric indices, physical activity, and dietary intake. For nutrient intake assessment, a valid food frequency questionnaire (FFQ) was used, and INQ was then calculated using the daily nutrient intake.

Results

After adjusting for age, FBS was significantly inverse associated with INQ for vitamins A (B = −0.193, p < 0.01), magnesium (B = −0.137, p < 0.01), phosphor (B = −0.175, p < 0.01), zinc (B = −0.113, p < 0.01), vitamin K (B = −0.197, p < 0.01), manganese (B = −0.111, p < 0.01) and selenium (B = −0.123, p < 0.01). The association between FBS and INQ for Se and Mn was disappeared after further adjustment for gender, body mass index (BMI), menopausal status, and total energy intake.

Conclusion

There was a significant inverse relationship between FBS and the INQ of vitamin A, manganese, phosphor, zinc, vitamin K, magnesium, and selenium. Prospective cohort studies should be conducted to establish a causal relationship between FBS and INQ.

Chemical constituents and medicinal properties of Allium species

Allium species, belonging to Alliaceae family, are among the oldest cultivated vegetables used as food. Garlic, onions, leeks and chives, which belong to this family, have been reported to have medicinal properties. The Allium species constituents have been shown to have antibacterial and antioxidant activities, and, in addition, other biological properties. These activities are related to their rich organosulfur compounds. These organosulfur compounds are believed to prevent the development of cancer, cardiovascular, neurological, diabetes, liver diseases as well as allergy and arthritis. There have also been reports on toxicities of these compounds. The major active compounds of Allium species includes, diallyl disulfide, diallyl trisulfide, diallyl sulfide, dipropyl disulfide, dipropyl trisulfide, 1-propenylpropyl disulfide, allyl methyl disulfide and dimethyl disulfide. The aim of this review is to focus on a variety of experimental and clinical reports on the effectiveness, toxicities and possible mechanisms of actions of the active compounds of garlic, onions, leek and chives.

Pharmacological Properties of Allium cepa, Preclinical and Clinical Evidences; A Review

Onion or Allium cepa (A. cepa) is one of the most important condiment plants grown and consumed all over the world. This plant has various therapeutic effects attributed to its constituents, such as quercetin, thiosulphinates and phenolic acids. In the present article, various pharmacological and therapeutic effects of A. cepa were reviewed. Different online databases using keywords such as onion, A. cepa, therapeutic effects, and pharmacological effects until the end of December 2019 were searched for this purpose. Onion has been suggested to be effective in treating a broad range of disorders, including asthma, inflammatory disorders, dysentery, wounds, scars, keloids and pain. In addition, different studies have demonstrated that onion possesses numerous pharmacological properties, including anti-cancer, anti-diabetic and anti-platelet properties as well as the effect on bone, cardiovascular, gastrointestinal, nervous, respiratory, and urogenital systems effects such as anti-osteoporosis, anti-hypertensive, antispasmodic, anti-diarrheal, neuro-protective, anti-asthmatic and diuretic effects. The present review provides detailed the various pharmacological properties of onion and its constituents and possible underlying mechanisms. The results of multiple studies suggested the therapeutic effect of onion on a wide range of disorders.

Organosulfur Compounds: A Review of Their Anti-inflammatory Effects in Human Health

Phytonutrients are widely recognized for providing protective human health benefits. Among the phytonutrients, epidemiological and experimental studies show that dietary organosulfur compounds (OSC) play a significant role in preventing various human pathological progressions, including chronic inflammation, by decreasing inflammatory mediators such as nitric oxide (NO), prostaglandin (PG)E₂, interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and IL-17, which are all typical hallmarks of inflammation. Evidence supports OSC in reducing the expression of these markers, thereby attenuating chronic inflammatory processes. Nuclear factor-kappa B (NF-κB) is a key regulating factor during inflammation, and novel evidence shows that OSC downregulates this transcriptional factor, thus contributing to the anti-inflammatory response. In vitro and in vivo studies show that inflammation is mechanistically linked with acute and chronic pathological conditions including cancer, diabetes, obesity, neural dysfunction, etc. Furthermore, a considerable number of experiments have demonstrated that the anti-inflammatory properties of OSC occur in a dose-dependent manner. These experiments also highlight indirect mechanisms as well as potent co-functions for protective roles as antioxidants, and in providing chemoprotection and neuroprotection. In this brief review, we provided an overview of the anti-inflammatory effects of OSC and elucidated probable mechanisms that are associated with inflammation and chronic disorders.

Onion bulb extract reduces colitis severity in mice via modulation of colonic inflammatory pathways and the apoptotic machinery

ETHNOPHARMACOLOGICAL RELEVANCE

The use of nutraceutical-based products has increased in recent years due to their demonstrated efficacy and their good safety profile. Onion is one of the most commonly used plants in the traditional medicine for the management of various conditions including inflammatory and gastrointestinal diseases. However, little is known regarding the molecular mechanism of the anti-inflammatory effects of onion particularly in inflammatory bowel disease (IBD).

AIM OF THE STUDY

To test the anti-inflammatory effects of onion bulb extract (OBE) in an IBD mouse model and the molecular mechanisms responsible for these effects such as modulation of the expression and/or the activity profile of various pro-inflammatory molecules.

MATERIALS AND METHODS

Colitis was induced in mice by dextran sulfate sodium (DSS) daily administration for 5 days. Animals were sacrificed, colons were removed and the severity of the inflammation was determined by the gross and histological assessments. The colonic level/activity of various cytokines and chemokines were measured using proteome profiling-based assay, western blotting, and immunofluorescence techniques.

RESULTS

DSS-induced colitis was significantly reduced by the daily OBE treatment and 5-aminosalicylic acid (5-ASA, positive control), particularly at 100-200 mg/kg doses, at both the gross and histological levels. OBE was also shown to reduce colonic expression and activity of several pro-inflammatory molecules and signaling pathways, such as mitogen activated protein kinase family, mammalian target of rapamycin, cyclooxygenase-2, and tissue inhibitors of metalloproteinases. In addition, OBE reduced the expression of interferon-γ, various C-C and C-X-C chemokines, and molecules involved in the apoptotic machinery such as cytochrome c, caspase-3 and -8, B-cell lymphoma-extra-large and -2.

CONCLUSIONS

OBE showed anti-inflammatory actions in IBD mouse model, which is attributed, in part, to the modulation of the expression and the activity of important pro-inflammatory molecules and signaling pathways involved in the inflammatory response. These data suggest that OBE may be a promising lead in the therapeutic management of IBD.

Phytomedicines Used for Diabetes Mellitus in Ghana: A Systematic Search and Review of Preclinical and Clinical Evidence

BACKGROUND

Available data indicate that diabetes mellitus leads to elevated cost of healthcare. This imposes a huge economic burden on households, societies, and nations. As a result many Ghanaians, especially rural folks, resort to the use of phytomedicine, which is relatively less expensive. This paper aims at obtaining information on plants used in Ghana to treat diabetes mellitus, gather and present evidence-based data available to support their uses and their mechanisms of action, and identify areas for future research.

METHOD

A catalogue of published textbooks, monographs, theses, and peer-reviewed articles of plants used in Ghanaian traditional medicine between 1987 and July 2018 for managing diabetes mellitus was obtained and used.

RESULTS

The review identified 76 plant species belonging to 45 families that are used to manage diabetes mellitus. Leaves were the part of the plants frequently used for most preparation (63.8%) and were mostly used as decoctions. Majority of the plants belonged to the Euphorbiaceae, Lamiaceae, Asteraceae, and Apocynaceae families. Pharmacological data were available on 23 species that have undergone in vitro studies. Forty species have been studied using in vivo animal models. Only twelve plants and their bioactive compounds were found with data on both preclinical and clinical studies. The records further indicate that medicinal plants showing antidiabetic effects did so via biochemical mechanisms such as restitution of pancreatic β-cell function, improvement in insulin sensitivity by receptors, stimulating rate of insulin secretion, inhibition of liver gluconeogenesis, enhanced glucose absorption, and inhibition of G-6-Pase, α-amylase, and α-glucosidase activities.

CONCLUSION

This review contains information on medicinal plants used to manage diabetes mellitus, including their pharmacological properties and mechanisms of action as well as models used to investigate them. It also provides gaps that can form the basis for further investigations and development into useful medications for effective treatment of diabetes mellitus.

Influence of Pickling Process on Allium cepa and Citrus limon Metabolome as Determined via Mass Spectrometry-Based Metabolomics

Brine, the historically known food additive salt solution, has been widely used as a pickling media to preserve flavor or enhance food aroma, appearance, or other qualities. The influence of pickling, using brine, on the aroma compounds and the primary and secondary metabolite profile in onion bulb Allium cepa red cv. and lemon fruit Citrus limon was evaluated using multiplex metabolomics technologies. In lemon, pickling negatively affected its key odor compound “citral”, whereas monoterpene hydrocarbons limonene and γ-terpinene increased in the pickled product. Meanwhile, in onion sulphur rearrangement products appeared upon storage, i.e., 3,5-diethyl-1,2,4-trithiolane. Profiling of the polar secondary metabolites in lemon fruit via ultra-performance liquid chromatography coupled to MS annotated 37 metabolites including 18 flavonoids, nine coumarins, five limonoids, and two organic acids. With regard to pickling impact, notable and clear separation among specimens was observed with an orthogonal projections to least squares-discriminant analysis (OPLS-DA) score plot for the lemon fruit model showing an enrichment of limonoids and organic acids and that for fresh onion bulb showing an abundance of flavonols and saponins. In general, the pickling process appeared to negatively impact the abundance of secondary metabolites in both onion and lemon, suggesting a decrease in their food health benefits.

Alleviation of Cardiac Damage by Dietary Fenugreek (Trigonella foenum-graecum) Seeds is Potentiated by Onion (Allium cepa) in Experimental Diabetic Rats via Blocking Renin-Angiotensin System

Hyperglycemia is one of the metabolic and homeostatic abnormalities that increase the cardiovascular mortality in diabetic patients by increased oxidative stress. We have recently reported amelioration of oxidative stress in cardiac tissue by dietary fenugreek (Trigonella foenum-graecum) seeds and onion (Allium cepa) in streptozotocin-induced diabetic rats. The mechanistic aspects of the cardio-protective influence of dietary fenugreek seeds (10%) and onion (3% powder) both individually and in combination on hyperglycemia-mediated cardiac damage was further investigated in this study on streptozotocin-induced diabetic rats. Cardio-protective influence of these dietary spices was evidenced by their blocking potential on renin-angiotensin system. This might be the consequence of reduced activation of angiotensin-converting enzyme (ACE) and angiotensin type 1 receptor (AT₁) in cardiac tissue. The combination produced an additive effect on ACE and AT₁ protein and mRNA expressions. Increased expression of type IV collagen, fibronectin, Bax, 4-hydroxynonenal, iNOS and metabolites of nitric oxide (nitrate/nitrite) along with disturbed PUFA-to-SFA ratio and activities of cardiac marker enzymes in blood confirmed the myocardial damage. Dietary fenugreek seed, onion and fenugreek + onion were found to ameliorate these pathological changes in the cardiovascular system. The beneficial effect being higher with the combination sometime amounting to additive (iNOS expression) or even a synergistic (cardiac Bax and type IV collagen expression and circulatory marker enzymes) in diabetic rats. Thus, the results of present investigation suggested that the combination of fenugreek seeds and onion offers higher beneficial influence in ameliorating cardiac damage accompanying diabetes.

Spice-Derived Bioactive Ingredients: Potential Agents or Food Adjuvant in the Management of Diabetes Mellitus

Spices possess tremendous therapeutic potential including hypoglycemic action, attributed to their bioactive ingredients. However, there is no study that critically reviewed the hypoglycemic potency, safety and the bioavailability of the spice-derived bioactive ingredients (SDBI). Therefore, the aim of the study was to comprehensively review all published studies regarding the hypoglycemic action of SDBI with the purpose to assess whether the ingredients are potential hypoglycemic agents or adjuvant. Factors considered were concentration/dosages used, the extent of blood glucose reduction, the IC50 values, and the safety concern of the SDBI. From the results, cinnamaldehyde, curcumin, diosgenin, thymoquinone (TQ), and trigonelline were showed the most promising effects and hold future potential as hypoglycemic agents. Conclusively, future studies should focus on improving the tissue and cellular bioavailability of the promising SDBI to achieve greater potency. Additionally, clinical trials and toxicity studies are with these SDBI are warranted.

Alleviation of oxidative stress-mediated nephropathy by dietary fenugreek (Trigonella foenum-graecum) seeds and onion (Allium cepa) in streptozotocin-induced diabetic rats

Oxidative stress plays a major role in the progression of diabetes and the pathogenesis of diabetic nephropathy. In this study, the beneficial influence of dietary fenugreek (Trigonella foenum-graecum) seeds and onion (Allium cepa) on oxidative stress-mediated renal injury was evaluated in streptozotocin-induced diabetic rats. Diabetes was induced in adult Wistar rats by the administration of streptozotocin (i.p. 45 mg kg^-1). Dietary interventions were made with 10% fenugreek seeds or 3% onion (freeze-dried) or their combination for 6 weeks. These dietary interventions countered nephromegaly in the diabetic animals, the increase in creatinine clearance and oxidative stress in renal tissue. These dietary interventions significantly countered the increased renal cholesterol and triglycerides associated with the diabetic condition. The up-regulation of the receptor for advanced glycation end products, inflammatory cytokines and oxidative stress markers in the renal tissue of the diabetic rats was effectively countered. Renal 8-hydroxy-2-deoxyguanosine, its excretion, DNA fragmentation and mitochondrial DNA deletion were significantly annulled in the diabetic rats by these dietary interventions. Generally, the beneficial effects were greater in the combined intervention, although they were not additive. Thus, the beneficial influence of dietary fenugreek and onion on oxidative stress-mediated renal injury is higher when consumed together and this may be a strategy to ameliorate diabetic nephropathy.

Fresh-Cut Onion: A Review on Processing, Health Benefits, and Shelf-Life

The ready-to-eat produce market has grown rapidly because of the health benefits and convenience associated with these products. Onion is widely used as an ingredient in an extensive range of recipes from breakfast to dinner and in nearly every ethnic cuisine. However, cutting/chopping of onion is a nuisance to many consumers due to the lachrymatory properties of the volatiles generated that bring tears to eyes and leave a distinct odor on hands. As a result, there is now an increasing demand for fresh-cut, value-added, and ready-to-eat onion in households, as well as large-scale uses in retail, food service, and various food industries, mainly due to the end-use convenience. Despite these benefits, fresh-cut onion products present considerable challenges due to tissue damage, resulting in chemical and physiological reactions that limit product shelf-life. Intensive discoloration, microbial growth, softening, and off-odor are the typical deteriorations that need to be controlled through the application of suitable preservation methods. This article reviews the literature related to the fresh-cut onion, focusing on its constituents, nutritional and health benefits, production methods, quality changes throughout storage, and technologies available to increase product shelf-life.

Evidences for diabetes and insulin mimetic activity of medicinal plants: Present status and future prospects

Diabetes mellitus (DM) is a considerable systemic metabolic disorder to exhibit various metabolic and cardiovascular disorders, mainly hyperglycemia. The global projected estimate of diabetes in 2030 will be about 439 million adults, out of which 300 million expected are of type-2 diabetes mellitus (T2DM). The present knowledge revealed responsible factors, occurrence and mechanism of these factors involved in the DM diseases. Hence, the aim of this review is to address and summarize the causes, plant resources, importance, present status and future programmes for diabetes control. The present review answers the contemporary present questions raised in the scientific field on DM. Two major problems are explained in detail about the autoimmune attack or dysfunction of β-cell and insulin resistance involved for Type 1 and Type 2 DM, respectively. Though there are various approaches to reduce the ill effects of diabetes and its secondary complications, many preferred herbal formulations due to lesser side effects and low cost. For this reason still it is getting increased attention in searching antidiabetic medicinal plants for hot research and to develop targeted medicine. Recurrence of islet autoimmunity lesson from pancreatic islet cell transplantation to cure T1D was outlined. With these highlights, the review summarizes the current knowledge on diabetes occurrence, factors (environmental and genetics), and types (I, II, gestation, and secondary DM), antidiabetic plants, sources for insulin mimetic plant principle compounds and their target mechanism with current and future trusted research areas for controlling of DM.

Semi-Continuous Fermentation of Onion Vinegar and Its Functional Properties

For the fermentation of vinegar using onion, acetic acid bacteria and yeast strains with high fermentation ability were screened. Among them, Saccharomyces cerevisiae 1026 was selected as a starter for ethanol production and Acetobacter orientalis MAK88 was selected as a vinegar producer. When the two-stage fermentation of onion vinegar was performed at 28 °C, the titratable acidity reached 4.80% at 24 h of fermentation. When semi-continuous fermentation proceeded to charge-discharge consisting of three cycles, the acetic acid content reached 4.35% at 48 h of fermentation. At this stage, the fermentation efficiency, acetic acid productivity, and specific product formation rate were 76.71%, 17.73 g/(L·d), and 20.58 g/(g·h), respectively. The process in this study significantly reduced the fermentation time and simplified the vinegar production process. The content of total flavonoids and total polyphenols in onion vinegar were 104.36 and 455.41 μg/mL, respectively. The antioxidant activities of onion vinegar in terms of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic) acid (ABTS⁺) radical scavenging activity, and reducing power were 75.33%, 98.88%, and 1.28, respectively. The nitrite scavenging abilities of onion vinegar were 95.38 at pH 1.2. The onion vinegar produced in this study showed higher organoleptic acceptability than commercial onion vinegar.

Amelioration of oxidative stress by dietary fenugreek (Trigonella foenum-graecum L.) seeds is potentiated by onion (Allium cepa L.) in streptozotocin-induced diabetic rats

Oxidative stress has a crucial role in the progression of diabetes and its complications. Soluble fibre-rich fenugreek seeds (Trigonella foenum-graecum L.) are understood to have a beneficial effect in the management of diabetes. Previously, we have shown that the amelioration of diabetic hyperglycemia and related metabolic abnormalities was potentiated by onion (Allium cepa L.) in experimental rats. The present study evaluated the additive beneficial effect of dietary fenugreek seeds (10%) and onion (3%) on oxidative stress in diabetic rats. These dietary interventions lowered oxidative stress, the combination producing a higher beneficial effect (p < 0.05), although not additive. Dietary fenugreek, onion, or fenugreek+onion countered hypercholesterolemia (p < 0.05), especially from low-density lipoprotein−associated fraction by 43%, 35%, and 54%, respectively. Elevated concentrations of cholesterol and triglycerides in the liver and heart under diabetic conditions were significantly counteracted by these dietary interventions, with the additive combination resulting in greater effect. These findings were also corroborated by restoration of histopathological abnormalities of heart and liver tissues along with lowered heart and liver weights. It is inferred that an alleviation of oxidative stress contributes further to the antidiabetic influence and this nutraceutical potential of fenugreek seeds and onion was higher when consumed together.

Effect of mahanimbine, an alkaloid from curry leaves, on high-fat diet-induced adiposity, insulin resistance, and inflammatory alterations

Spices and condiments, small but an integral part of the daily diet, are known to affect physiological functions. This study evaluated the effects of mahanimbine, a major carbazole alkaloid from Murraya koenigii (curry leaves), against progression of high-fat diet (HFD)-induced metabolic complications in mice (male and female). Mahanimbine at 2 mg/kg (HFD + LD) and 4 mg/kg (HFD + HD) of body weight was administered daily along with HFD feeding for 12 weeks. At the end of the study, male HFD + LD and HFD + HD groups showed 51.70 ± 3.59% and 47.37 ± 3.73% weight gain, respectively, as compared with 71.02 ± 6.04% in HFD fed mice whereas female HFD + LD and HFD + HD groups showed 24.31 ± 1.68% and 25.10 ± 2.61% weight gain as compared with HFD group with 36.69 ± 3.60% of weight gain. Mahanimbine prevented HFD-induced hyperlipidemia and fat accumulation in adipose tissue and liver along with the restricted progression of systemic inflammation and oxidative stress. Moreover, mahanimbine treatment improved glucose clearance and upregulated the expression of insulin responsive genes in liver and adipose tissue. Male and female mice showed different traits in development of HFD-induced metabolic disturbances; however, mahanimbine treatment exerted similar effects in both the sexes. In addition, mahanimbine lowered the absorption of dietary fat resulting in dietary fat excretion. In conclusion, daily consumption of mahanimbine and thereby curry leaves may alleviate development of HFD-induced metabolic alterations. © 2016 BioFactors, 43(2):220-231, 2017.

Biological Activities of Red Pepper (Capsicum annuum) and Its Pungent Principle Capsaicin: A Review

Capsaicin, the pungent alkaloid of red pepper (Capsicum annuum) has been extensively studied for its biological effects which are of pharmacological relevance. These include: cardio protective influence, antilithogenic effect, antiinflammatory, and analgesia, thermogenic influence, and beneficial effects on gastrointestinal system. Therefore, capsaicinoids may have the potential clinical value for pain relief, cancer prevention and weight loss. It has been shown that capsaicinoids are potential agonists of capsaicin receptor (TRPV1). They could exert the effects not only through the receptor-dependent pathway but also through the receptor-independent one. The involvement of neuropeptide Substance P, serotonin, and somatostatin in the pharmacological actions of capsaicin has been extensively investigated. Topical application of capsaicin is proved to alleviate pain in arthritis, postoperative neuralgia, diabetic neuropathy, psoriasis, etc. Toxicological studies on capsaicin administered by different routes are documented. Capsaicin inhibits acid secretion, stimulates alkali and mucus secretion and particularly gastric mucosal blood flow which helps in prevention and healing of gastric ulcers. Antioxidant and antiinflammatory properties of capsaicin are established in a number of studies. Chemopreventive potential of capsaicin is evidenced in cell line studies. The health beneficial hypocholesterolemic influence of capsaicin besides being cardio protective has other implications, viz., prevention of cholesterol gallstones and protection of the structural integrity of erythrocytes under conditions of hypercholesterolemia. Beneficial influences of capsaicin on gastrointestinal system include digestive stimulant action and modulation of intestinal ultrastructure so as to enhance permeability to micronutrients.

The Protective Effect of Antioxidants Consumption on Diabetes and Vascular Complications

Obesity and diabetes is generally accompanied by a chronic state of oxidative stress, disequilibrium in the redox balance, implicated in the development and progression of complications such as micro- and macro-angiopathies. Disorders in the inner layer of blood vessels, the endothelium, play an early and critical role in the development of these complications. Blunted endothelium-dependent relaxation and/or contractions are quietly associated to oxidative stress. Thus, preserving endothelial function and oxidative stress seems to be an optimization strategy in the prevention of vascular complications associated with diabetes. Diet is a major lifestyle factor that can greatly influence the incidence and the progression of type 2 diabetes and cardiovascular complications. The notion that foods not only provide basic nutrition but can also prevent diseases and ensure good health and longevity is now attained greater prominence. Some dietary and lifestyle modifications associated to antioxidative supply could be an effective prophylactic means to fight against oxidative stress in diabesity and complications. A significant benefit of phytochemicals (polyphenols in wine, grape, teas), vitamins (ascorbate, tocopherol), minerals (selenium, magnesium), and fruits and vegetables in foods is thought to be capable of scavenging free radicals, lowering the incidence of chronic diseases. In this review, we discuss the role of oxidative stress in diabetes and complications, highlight the endothelial dysfunction, and examine the impact of antioxidant foods, plants, fruits, and vegetables, currently used medication with antioxidant properties, in relation to the development and progression of diabetes and cardiovascular complications.

Antihyperlipidemic activity of Allium chinense bulbs

Allium chinense is a medicinal plant and nutritional food commonly used in Eastern Asia. In this study, we investigated the in vitro antioxidant activity (scavenging of α,α-diphenyl-β-picrylhydrazyl free radical, total phenol content, reducing power, and total antioxidant activity) and constituents of various extracts from A. chinense. Moreover, we also studied the in vivo hypolipidemic effects of extracts on high-fat-diet Wistar rats. Ethanol extracts from A. chinense showed notable antioxidant activity, and its high-dose essential-oil extract both significantly reduced serum and hepatic total cholesterol, triglyceride, and low-density lipoprotein levels and increased serum high-density lipoprotein levels in high-fat-diet Wistar rats compared with those observed following treatment with the control drug probucol. Additionally, visceral fat in high-fat-diet Wistar rats was reduced. Furthermore, groups with high doses of essential-oil and residue extracts showed protective effects associated with histopathological liver alteration. These results suggested that A. chinense is a valuable plant worthy of further investigation as a potential dietary supplement or botanical drug.

Consumption of Fresh Yellow Onion Ameliorates Hyperglycemia and Insulin Resistance in Breast Cancer Patients During Doxorubicin-Based Chemotherapy: A Randomized Controlled Clinical Trial

PURPOSE

Doxorubicin has been found to be associated with insulin resistance in animal models. Onion, a so-called functional food, is noted to affect the insulin signaling pathway of diabetes in vitro. To our knowledge, this is the first study to investigate the effects of consuming fresh yellow onions on insulin-related indices compared with a low-onion-containing diet among breast cancer (BC) patients treated with doxorubicin.

METHODS

This parallel-design, randomized, triple-blind, controlled clinical trial was conducted on 56 eligible BC patients (aged 30-63 years), diagnosed with invasive ductal carcinoma. Following their second cycle of chemotherapy, subjects were assigned in a stratified-random allocation to receive body mass index-dependent 100 to 160 g/d of onion as high onion group (HO; n = 28) or 30 to 40 g/d small onions in low onion group (LO; n = 28) for 8 weeks intervention. Participants, care givers, and those who assessed laboratory analyses were blinded to the assignments (IRCT Registry No.: IRCT2012103111335N1).

RESULTS

The compliance level of participants in the analysis was as high as 87.85%. A total of 23 available cases was analyzed in each group. The daily use of HO resulted in a significant decrease in serum fasting blood glucose and insulin levels in comparison with LO, over the period of study ( P < .001). Posttreatment with HO showed a significant decrease in homeostasis model of assessment-insulin resistance relative to changes in the LO group ( P < .05). A comparison of the changes that occurred throughout pre- and postdose treatments indicated improved quantitative insulin sensitivity check index ( P < .05) and controls on C-peptide in the HO group ( P < .05).

CONCLUSIONS

The present study demonstrated the effectiveness of onion to ameliorate hyperglycemia and insulin resistance in BC during doxorubicin-based chemotherapy.

Enhancing Effect of Lipids and Emulsifiers on the Accumulation of Quercetin Metabolites in Blood Plasma after the Short-term Ingestion of Onion by Rats

The effects of co-ingested lipids and emulsifiers on the accumulation of quercetin metabolites in blood plasma after the short-term ingestion of onion by rats were investigated. Plasma extracts of rats that had been fed onion-containing diets for one and two weeks were analyzed by HPLC with electrochemical detection after a treatment with sulfatase/beta-glucuronidase. Almost all of the quercetin metabolites in the plasma were sulfate/glucuronide conjugates of quercetin and isorhamnetin. More than 4.6% (w/w) of soybean oil in the diets significantly enhanced the accumulation of quercetin metabolites in the plasma. Fish oil and beef tallow increased this to an extent similar to that with soybean oil, and lecithin was more effective than the other three lipids. Two emulsifiers, sodium caseinate and sucrose fatty acid ester, also showed an enhancing effect on the accumulation of quercetin metabolites. These results indicate that co-ingested lipids and emulsifiers could enhance the bioavailability of quercetin glucosides in onion.

Alleviating Effects of Baechu Kimchi Added Ecklonia cava on Postprandial Hyperglycemia in Diabetic Mice

In this study, we investigated the inhibitory effects of Baechu kimchi added Ecklonia cava on the activities of α-glucosidase and α-amylase and its alleviating effect on the postprandial hyperglycemia in STZ-induced diabetic mice. Baechu kimchi added Ecklonia cava (BKE, 15%) was fermented at 5°C for 28 days. Optimum ripened BKE was used in this study as it showed the strongest inhibitory activities on α-glucosidase and α-amylase by fermentation time among the BKEs in our previous study. The BKE was extracted with 80% methanol and the extract solution was concentrated, and then used in this study. The BKE extract showed higher inhibitory activities than Baechu kimchi extract against α-glucosidase and α-amylase. The IC₅₀ values of the BKE extract against α-glucosidase and α-amylase were 0.58 and 0.35 mg/mL, respectively; BKE exhibited a lower α-glucosidase inhibitory activity but a higher α-amylase inhibitory activity than those of acarbose. The BKE extract alleviated postprandial hyperglycemia caused by starch loading in normal and streptozotocin-induced diabetic mice. Furthermore, the BKE extract significantly lowered the incremental area under the curve in both normal and diabetic mice (P<0.05). These results indicated that the BKE extract may delay carbohydrate digestion and thus glucose absorption.

In vivo Investigation of Anti-diabetic Properties of Ripe Onion Juice in Normal and Streptozotocin-induced Diabetic Rats

The acute and subacute hypoglycemic and antihyperglycemic effects of drinkable ripe onion juice (Commercial product name is “Black Onion Extract”) were investigated in normal and streptozotocin-induced diabetic rats. For tests of acute and subacute hypoglycemic effects, ripe onion juice (5 and 15 mL/kg b.w.) was administered by oral gavage to normal Sprague Dawley rats and measurements of fasting glucose levels and oral glucose tolerance tests were performed. Tolbutamide was used as a reference drug at a single oral dose of 250 mg/kg b.w. To test anti-hyper-glycemic activity, the ripe onion juice was administered to streptozotocin-induced diabetic rats by oral gavage at single dose of 15 mL/kg b.w. per day for 7 consecutive days. Oral administration of the ripe onion juice at either dosed level of 5 or 15 mL/kg b.w. showed no remarkable acute hypoglycemic effect in normal rats. The two dosed levels caused a relatively small reduction, only 18% and 12% (5 and 15 mL/kg b.w., respectively) decrease in glucose levels at 2 h after glucose loading in normal rats. However, at 3 h after glucose loading, blood glucose levels in the ripe onion juice-dosed rats were decreased to the corresponding blood glucose level in tolbutamide-dosed rats. Although showing weak hypoglycemic potential compared to that of tolbutamide, oral administration of ripe onion juice (15 mL/kg b.w.) for a short period (8 days) resulted in a slight reduction in the blood glucose levels that had elevated in Streptozotocin-induced diabetic rats. In conclusion, these results suggest that the commercial product “Black Onion Extract” may possess anti-hyperglycemic potential in diabetes.

Review of the mechanism of cell death resulting from streptozotocin challenge in experimental animals, its practical use and potential risk to humans

Streptozotocin (STZ) (2-deoxy-2-({[methyl(nitroso)amino]carbonyl}amino)-β-D-glucopyranose) is a naturally occurring diabetogenic compound, produced by the soil bacterium streptomyces achromogenes, that exhibits broad spectrum of antibacterial properties. Streptozotocin functions as a DNA synthesis inhibitor in both bacterial and mammalian cells. In mammalian cells, the actual mechanism and metabolic targets of STZ toxicity that results in cell death is not known. This review identifies four key areas that explain the mechanism of the cytotoxicity of STZ in mammalian cell lines, investigates the practical aspects of using STZ in experimental animals and the potential risks of its exposure to human health.

Dietary spices as beneficial modulators of lipid profile in conditions of metabolic disorders and diseases

Spices are valued for their medicinal properties besides their use as food adjuncts to enhance the sensory quality of food. Dietary garlic, onion, fenugreek, red pepper, turmeric, and ginger have been proven to be effective hypocholesterolemics in experimentally induced hypercholesterolemia. The hypolipidemic potential of fenugreek in diabetic subjects and of garlic and onion in humans with induced lipemia has been demonstrated. Capsaicin and curcumin - the bioactive compounds of red pepper and turmeric - are documented to be efficacious at doses comparable to usual human intake. Capsaicin and curcumin have been shown to be hypotriglyceridemic, thus preventing accumulation of fat in the liver under adverse situations by enhancing triglyceride transport out of the liver. Capsaicin, curcumin, fenugreek, ginger, and onion enhance secretion of bile acids into bile. These hypocholesterolemic spices/spice principles reduce blood and liver cholesterol by enhancing cholesterol conversion to bile acids through activation of hepatic cholesterol-7α-hydroxylase. Many human trials have been carried out with garlic, onion, and fenugreek. The mechanism underlying the hypocholesterolemic and hypotriglyceridemic influence of spices is fairly well understood. Health implications of the hypocholesterolemic effect of spices experimentally documented are cardio-protection, protection of the structural integrity of erythrocytes by restoration of membrane cholesterol/phospholipid profile and prevention of cholesterol gallstones by modulation of the cholesterol saturation index in bile.

Functional herbal food ingredients used in type 2 diabetes mellitus

From many reports it is clear that diabetes will be one of the major diseases in the coming years. As a result there is a rapidly increasing interest in searching new medicines, or even better searching prophylactic methods. Based on a large number of chemical and pharmacological research work, numerous bioactive compounds have been found in functional herbal food ingredients for diabetes. The present paper reviews functional herbal food ingredients with regards to their anti-diabetic active principles and pharmacological test results, which are commonly used in Asian culinary system and medical system and have demonstrated clinical or/and experimental anti-diabetic effectiveness. Our idea of reviewing this article is to give more attention to these functional food ingredients as targets medicinal foods in order to prevent or slow down the development of type 2 diabetes mellitus.

Lowering effects of onion intake on oxidative stress biomarkers in streptozotocin-induced diabetic rats

The protective effect of onion against oxidative stress in streptozotosin-induced diabetic rats was investigated in comparison with that of quercetin aglycone. We measured oxidative stress biomarkers involving the susceptibility of the plasma against copper ion-induced lipid peroxidation, which was estimated by the amounts of thiobarbituric acid-reactive substances (TBARS) and cholesteryl ester hydroperoxides, and urine TBARS and 8-hydroxydeoxyguanosine contents. After the 12-week feeding period, plasma glucose levels and these biomarkers increased in diabetic rats compared to normal rats. In diabetic rats fed a 6.0% onion diet (quercetin equivalent: 0.023%), quercetin metabolites accumulated in the plasma at concentrations of approximately 35 microM. Onion intake decreased plasma glucose levels and lowered the oxidative stress biomarkers. On the other hand, quercetin metabolites in the plasma of rats fed a diet with 0.023% quercetin aglycone were found at lower concentrations (14.2 microM) than the rats fed the onion diet. Furthermore, oxidative stress biomarkers were higher in the quercetin diet group compared to the onion diet group. These results strongly suggest that onion intake suppresses diabetes-induced oxidative stress more effectively than the intake of the same amount of quercetin aglycone alone.

Onion peel extracts ameliorate hyperglycemia and insulin resistance in high fat diet/streptozotocin-induced diabetic rats

BACKGROUND

Quercetin derivatives in onions have been regarded as the most important flavonoids to improve diabetic status in cells and animal models. The present study was aimed to examine the hypoglycemic and insulin-sensitizing capacity of onion peel extract (OPE) containing high quercetin in high fat diet/streptozotocin-induced diabetic rats and to elucidate the mechanism of its insulin-sensitizing effect.

METHODS

Male Sprague-Dawley rats were fed the AIN-93G diet modified to contain 41.2% fat and intraperitoneally injected with a single dose of streptozotocin (40 mg/kg body weight). One week after injection, the rats with fasting blood glucose levels above 126 mg/dL were randomly divided into 4 groups to treat with high fat diet containing 0 (diabetic control), 0.5, or 1% of OPE or 0.1% quercetin (quercetin equivalent to 1% of OPE) for 8 weeks. To investigate the mechanism for the effects of OPE, we examined biochemical parameters (insulin sensitivity and oxidative stresses) and protein and gene expressions (pro-inflammatory cytokines and receptors).

RESULTS

Compared to the diabetic control, hypoglycemic and insulin-sensitizing capability of 1% OPE were demonstrated by significant improvement of glucose tolerance as expressed in incremental area under the curve (P = 0.0148). The insulin-sensitizing effect of OPE was further supported by increased glycogen levels in liver and skeletal muscle (P < 0.0001 and P = 0.0089, respectively). Quantitative RT-PCR analysis showed increased expression of insulin receptor (P = 0.0408) and GLUT4 (P = 0.0346) in muscle tissues. The oxidative stress, as assessed by superoxide dismutase activity and malondialdehyde formation, plasma free fatty acids, and hepatic protein expressions of IL-6 were significantly reduced by 1% OPE administration (P = 0.0393, 0.0237, 0.0148 and 0.0025, respectively).

CONCLUSION

OPE might improve glucose response and insulin resistance associated with type 2 diabetes by alleviating metabolic dysregulation of free fatty acids, suppressing oxidative stress, up-regulating glucose uptake at peripheral tissues, and/or down-regulating inflammatory gene expression in liver. Moreover, in most cases, OPE showed greater potency than pure quercetin equivalent. These findings provide a basis for the use of onion peel to improve insulin insensitivity in type 2 diabetes.

Hypolipidemic and antioxidant efficacy of dehydrated onion in experimental rats

Hypolipidemic and antioxidant potency of a dehydrated onion product was evaluated in experimental rats maintained for 6 weeks at 5 and 10% dietary levels. Serum cholesterol especially low-density lipoprotein was significantly reduced by dietary dehydrated onion in hypercholesterolemic rats. This was associated with an increase in high density lipoprotein cholesterol. Blood triglyceride concentration in hypercholesterolemic rats was lower in onion supplemented diet group. Glutathione, ascorbic acid and α-tocopherol in the blood of hypercholesterolemic rats were higher in onion treatment, while lipid peroxides were lower. Hepatic α-tocopherol concentration was higher in rats maintained on onion diets, while lipid peroxides were reduced. Thus, this study has proved significant cholesterol lowering and antioxidant effect of dehydrated onion product.

Evaluation of tolerable levels of dietary quercetin for exerting its antioxidative effect in high cholesterol-fed rats

The tolerable level of dietary quercetin for exerting its antioxidative effect was evaluated in high cholesterol-fed rats, using quercetin-containing diets (31-1260 mg quercetin/kg body weight/day) and onion diets (19-94 mg quercetin aglycone equivalent/kg body weight/day), from the viewpoint of a safety assessment. After feeding for 4 weeks, the urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) levels of the quercetin-containing diet groups fed more than 157 mg quercetin/kg body weight/day were higher than the group fed a quercetin-free diet, although the plasma quercetin metabolite levels and plasma antioxidative activity were elevated depending on the amounts of quercetin or onion diet intake. No significant effect on body weight gain by quercetin-containing diets or onion diets was observed. However, ratios of the liver and kidney weights to the body weight were significantly increased in the quercetin-containing diet groups fed more than 314 mg and 157 mg quercetin/kg body weight/day, respectively, and in the onion diet groups fed more than 47 mg quercetin aglycone equivalent/kg body weight/day. These results indicated that the tolerable level for dietary quercetin for exerting its antioxidative effect was between 126 and 157 mg/kg/day for the quercetin diet and between 19 and 34 mg/kg/day for the onion diet.

Antidiabetic effect of Korean traditional Baechu (Chinese cabbage) kimchi in a type 2 diabetes model of rats

The present study was conducted to examine the antidiabetic effects of two dietary dosages (0.5% and 2.0%) of freeze-dried Korean traditional Baechu (Chinese cabbage) kimchi in a high-fat (HF) diet-fed, streptozotocin (STZ)-induced type 2 diabetes (T2D) rat model. Five-week-old male Sprague-Dawley rats were fed HF diet for 2 weeks and then randomly divided into four groups of eight animals: normal control (NC), diabetic control (DBC), kimchi low (KML) (0.5%), and kimchi high (KMH) (2.0%) groups. Diabetes was induced by an intraperitoneal injection of STZ (40 mg/kg of body weight) in all groups except the NC group. After 4 weeks of feeding of experimental diets, serum insulin concentrations and Homeostatic Model Assessment pancreatic beta-cell function were increased and blood glycated hemoglobin was decreased in the kimchi-fed groups compared to the DBC group, while a significant (P < .05) difference was observed only in the KMH group for serum insulin concentration. Lower fasting blood glucose and better glucose tolerance were observed in the KMH group compared to the DBC and KML groups; however, differences were not significant. Food intake, body weight gain, Homeostatic Model Assessment insulin resistance index, and serum lipid profiles were not significantly influenced by kimchi-containing diets. Data of this study suggest that dietary Baechu kimchi has some antidiabetic effects even when fed with a HF-containing diet. Better results are possible if it is consumed with normal or low-fat rather than HF-containing diet.

Dietary red chilli (Capsicum frutescens L.) is insulinotropic rather than hypoglycemic in type 2 diabetes model of rats

The present study was conducted to clarify whether a low or a high, but tolerable, dietary dose of red chilli (RC) can ameliorate the diabetes related complications in a high-fat (HF) diet-fed streptozotocin (STZ)-induced type 2 diabetes model of rats. Five-week-old male Sprague Dawley rats were fed a HF diet for 2 weeks then randomly divided into four groups namely: normal control (NC), diabetic control (DBC), red chilli low (RCL, 0.5%) and red chilli high (RCH, 2.0%) groups. Diabetes was induced by an intraperitoneal (i.p.) injection of STZ (40 mg/kg BW) in all groups except the NC group. After 4 weeks feeding of experimental diets, the fasting blood glucose concentrations in both RC fed groups were not significantly different. The serum insulin concentration was significantly (p < 0.05) increased in the RCH group compared with the DBC and RCL groups. Blood HbA1c, liver weight, liver glycogen and serum lipids were not influenced by the feeding of RC-containing diets. The data of this study suggest that 2% dietary RC is insulinotropic rather than hypoglycemic at least in this experimental condition.

Gluconeogenic Substrates and Hepatic Gluconeogenic Enzymes in Streptozotocin-Diabetic Rats: Effect of Mulberry (Morus indicaL.) Leaves

Mulberry (Morus indica L.) leaves, the sole food of the silk worm, were evaluated for antidiabetic effects in streptozotocin (STZ)-diabetic rats. Treatment with dried mulberry leaf powder at 25% of the diet for a period of 8 weeks was found to be remarkably beneficial to STZ-diabetic rats as evidenced by controlled hyperglycemia and glycosuria. In addition, mulberry leaves countered (reversed) the alterations in gluconeogenic substrates in STZ-diabetic rats as indicated by significant reduction in serum pyruvic and lactic acid levels, a significant increase in proteins and a significant decrease in free amino acid, urea, and creatinine levels in blood, and a decreased urinary excretion of urea and creatinine. Anomalies in the activities of hepatic gluconeogenic enzymes associated with impaired glucose homeostasis in STZ-diabetic rats were ameliorated by feeding the mulberry leaf-supplemented diet, indicating that control over hyperglycemia and associated complications in the diabetic state by mulberry leaves is by way of regulation of gluconeogenesis. With respect to all the parameters, mulberry leaves were more effective than the oral hypoglycemic drug glibenclamide.

Leads from Indian medicinal plants with hypoglycemic potentials

Diabetes mellitus is caused due to deficiency in production of insulin by the pancreas, or by the ineffectiveness of the insulin produced. It is a global problem and number of those affected is increasing day by day. The plants provide a potential source of hypoglycemic drugs because many plants and plant derived compounds have been used in the treatment of diabetes. Several medicinal plants have found potential use as hypoglycemic in the Indian system of medicines, including ayurveda. Many Indian plants have been investigated for their beneficial use in different types of diabetes and reports occur in numerous scientific journals. This article aims to provide a comprehensive review on various plant species from Indian biosphere and their constituents, which have been shown to display potent hypoglycemic activity. The use of herbs as hypoglycemic is a major avenue in Indian perspectives particularly for treating diabetes, which require to be explored more effectively as there are so many literatures available on these aspects. This paper describes the chemistry, activity and usage of the constituents isolated from these plants from India for the treatment of diabetes.

Effect of Japanese radish (Raphanus sativus) sprout (Kaiware-daikon) on carbohydrate and lipid metabolisms in normal and streptozotocin-induced diabetic rats

No information is available about the effects of Japanese radish sprout (JRS) on diabetes. To clarify the effects, the influence of JRS on carbohydrate and lipid metabolisms was investigated in normal and streptozotocin-induced diabetic rats. The rats were fed a diet containing 0%, 2.5% or 5% of JRS ad libitum for 21 days. Compared with the corresponding control groups, the JRS-fed normal rats showed lower plasma levels of total cholesterol (TC), triglycerides (TG), phospholipids (PL), fructosamine, glucose and insulin and higher plasma levels of low-density lipoprotein-cholesterol, whereas the JRS-fed diabetic rats showed lower plasma levels of fructosamine, glucose and insulin without changes in the plasma lipid parameters. JRS also decreased the hepatic TC, TG and PL levels in the normal rats and the TG level in the diabetic rats. These results showed that JRS had a hypoglycemic activity in both the normal and diabetic rats and partly improved lipid metabolism in the normal rats. JRS has the potential to alleviate hyperglycemia in cases where diabetes is present and to serve in the primary prevention of diabetes mellitus.

Plant foods in the management of diabetes mellitus: spices as beneficial antidiabetic food adjuncts

Diet has been recognized as a corner stone in the management of diabetes mellitus. Spices are the common dietary adjuncts that contribute to the taste and flavour of foods. Besides, spices are also known to exert several beneficial physiological effects including the antidiabetic influence. This review considers all the available information from animal experimentation as well as clinical trials where spices, their extracts or their active principles were examined for treatment of diabetes. Among the spices, fenugreek seeds (Trigonella foenumgraecum), garlic (Allium sativum), onion (Allium cepa), and turmeric (Curcuma longa) have been experimentally documented to possess antidiabetic potential. In a limited number of studies, cumin seeds (Cuminum cyminum), ginger (Zingiber officinale), mustard (Brassica nigra), curry leaves (Murraya koenigii) and coriander (Coriandrum sativum) have been reported to be hypoglycaemic.

Transient receptor potential vanilloid subfamily 1 expressed in pancreatic islet beta cells modulates insulin secretion in rats

Capsaicin-sensitive afferent neurons including transient receptor potential vanilloid subfamily 1, TRPV1, and neurohormonal peptides participate in the physiological regulation of pancreatic endocrine. However, the direct effect of capsaicin on insulin secretion remains unknown. Our present study showed that TRPV1 is expressed in islet beta cells as well as in neurons in rat pancreas, and also in rat beta cell lines, RIN and INS1. Capsaicin (10(-11)-10(-9) M) dose-dependently increased insulin secretion from RIN cells, and this effect was inhibited by either a TRPV1 inhibitor capsazepine or EDTA. Systemic capsaicin (10 mg/kg, s.c.) increased plasma insulin level 1 h after the treatment. We demonstrated for the first time that TRPV1 is functionally expressed in rat islet beta cells and plays a role in insulin secretion as a calcium channel. This study may account for the influences of capsaicin on the food intake and energy consumption as well as on the pathophysiological regulation of pancreatic endocrine.